Biomaterial Database

Hypoxanthine-DNA glycosylase from Escherichia coli. Partial purification and properties. 1988

I Harosh, and J Sperling

Department of Organic Chemistry, Weizmann Institute of Science, Rehovot, Israel.

Hypoxanthine-DNA glycosylase from Escherichia coli was partially purified by ammonium sulfate fractionation and by chromatography on Sephacryl S-200, DEAE-cellulose, and phosphocellulose P-11 columns. Analysis of the enzymatic reaction products was carried out on a minicolumn of DEAE-cellulose and/or by paper chromatography, by following the release of the free base [3H]hypoxanthine from [3H]dIMP-containing phi X174 DNA. In native conditions, the enzyme has a molecular mass of 60 +/- 4 kDa, as determined by gel filtration on Sephadex G-150 and Sephacryl S-200 columns. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed a major polypeptide band of an apparent molecular mass of 56 kDa, and glycerol gradient centrifugation indicated a sedimentation coefficient of 4.0 S. Hypoxanthine-DNA glycosylase from E. coli has an obligatory requirement for Mg2+ and is totally inhibited in the presence of EDTA. Co2+ can only partially replace Mg2+. The enzyme is inhibited by hypoxanthine which at 4 mM causes 85% inhibition. The optimal pH range of the enzymatic activity is 5.5-7.8, and the apparent Km value is 2.5 x 10(-7) M.

UI	MeSH Term	Description	Entries
D007042	Hypoxanthines	Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
D007291	Inosine Monophosphate	Inosine 5'-Monophosphate. A purine nucleotide which has hypoxanthine as the base and one phosphate group esterified to the sugar moiety.	IMP,Inosinic Acid,Ribosylhypoxanthine Monophosphate,Inosinic Acids,Sodium Inosinate,Acid, Inosinic,Acids, Inosinic,Inosinate, Sodium,Monophosphate, Inosine,Monophosphate, Ribosylhypoxanthine
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010584	Bacteriophage phi X 174	The type species of the genus MICROVIRUS. A prototype of the small virulent DNA coliphages, it is composed of a single strand of supercoiled circular DNA, which on infection, is converted to a double-stranded replicative form by a host enzyme.	Coliphage phi X 174,Enterobacteria phage phi X 174,Phage phi X 174,phi X 174 Phage,Phage phi X174
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D002845	Chromatography	Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.	Chromatographies
D002854	Chromatography, Paper	An analytical technique for resolution of a chemical mixture into its component compounds. Compounds are separated on an adsorbent paper (stationary phase) by their varied degree of solubility/mobility in the eluting solvent (mobile phase).	Paper Chromatography,Chromatographies, Paper,Paper Chromatographies
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA